Kidney diseases can have differing causes. Various forms of infection in kidney tissue (glomerulonephritis) often leave lasting damage. Even high blood pressure (hypertension), a common ailment, can profoundly damage the kidneys. An underlying diabetes is oftentimes the cause of kidney disease and an excessive intake of certain medications can also reduce long-term kidney function. Various other, sometimes congenital, causes exist, such as polycystic kidney disease. Most kidney diseases develop quietly and are not noticed for many years. Therefore, some with chronic kidney disease do not visit a kidney specialist (nephrologist) until a late stage of the illness. Though seldom, some cases can develop quickly in a matter of days or weeks resulting in acute renal failure.